James brockie



(No Model.)

J. BROGKIE. ELECTRIC ARC LAMP.

o. 486,757. Patented Nov. 22, 1892.

UNITED STATES PATENT OFFICE.

JAMES BROOKIE, OF LONDON, ENGLAND.

ELECTRIC-ARC LAM P.

SPECIFICATION forming part of Letters Patent No. 486,757, dated November22, 1892.

Application filed August 6, 1891.

To all whom it may concern:

Be it known that 1, JAMES BROCKIE', a citizen of England, residing atSouth Road, Oamberwell, London, in the county of Surrey, England, haveinvented a certain new and useful Improvement in the RegulatingMechanism of Electric-Arc Lamps, of which the following is aspecification.

My invention relates to improved mechanism for efiecting by means of apair of solenoids automatic control of the clutch or other feedingdevice of an electric-arc lamp, as I shall describe, referring to theaccompanying drawings, illustrating diagrammatically the arrangement ofsolenoids which I adopt for this purpose.

Figure 1 is a diagram showing the condition of the parts when inert, thelamp being out of circuit. Fig. 2 shows the condition when the arc isstruck. Fig. 3 showsamodification.

A is a solenoid having its coil in the lampcircuit, this coil requiringto have comparatively few convolntionsa of coarse wire, because when ithas to separate the carbons for striking the are it is aided by part ofthe core of B, which is a solenoid having its coil b of fine wire in ashunt to the lamp-circuit. This solenoid may, however, have severalconvolutions 1) of coarse wire in the lamp-circuit along with those ofA, these convolutions being wound or connected so as to give to thesolenoid the same polarity as that given by the shunt-coil. The coreO'ofthe solenoidA is linked by a non-magnetic rod F to one end of alever L. The core of the solenoid B is made in two parts D and E, whichtogether make up the same length as C, but only the upper part D islinked to the lever L by a nonmagnetic rod G. A thin non-magnetic tube Tmay be fixed on either D or E to serve as a guide to keep the two partsof the core in line with one another.

The lever L is connected to any suitable clutch or other known feedmechanism by which the carbons are moved apart, brought near together,and advanced as they are consumed, this feed mechanism being controlledby the operation of the solenoids A and B. As an example, I have shownin Figs. 1 and 2 a known form of clutch consisting of a washer K,surrounding the carbon M, leaving Serial No. 401,896. (No model.)

it free when the washer is horizontal, as in Fig. 1, but gripping itwhen itis canted to an inclination, as in Fig. 2.

When the lamp is not in circuit, the two solenoids are inert and thecores 0 and E rest on a base H or on suitable stops, as shown in Fig. 1.When the lamp is put in circuit, the core 0 is attracted upward, and thepart core D is attracted downward, both conspiring to raise the rightend of the lever L, and thus to cant and raise the washer K, as shown inFig. 2, causing separation of the carbons and striking the arc. By thesame movement the part core D meets the part E, and both beingmagnetized they adhere together, and then operate as one core acting onthe lever L, in

conjunction with the core C, so as to determine the separation orapproach ofthe carbons. When the carbons are too near, the solenoid Aexerts greater power to raise C than B does to raise D and E, andconsequently the lever L is moved toward the attitude shown in Fig. 2,causj;ng separation of the carbons. When the carbons are too far apart,B exerts greater power to raise D and E than A does to raise 0.Consequently the lever L is moved toward the attitude shown in Fig. 1,allowing approach and feed of the can bons.

According to the modification shown in Fig. 3, the core of B isundivided;butthe coreof A has its upper part O separated from the lowerpart 0 which is linked to a lever L to control the feed mechanism, thelever L merely acting as the connection of the two cores. With thisarrangement when the lamp is out of circuit and the solenoids inert theparts are as shown in Fig. 3. When the lamp is put in circuit the core 0is attracted upward, moving L, and so causing the arc to be struck. Atthe same time O is attracted downward, and when it meets O the two partsadhere together as one core, operating with the core of B, as abovedescribed with reference to Figs 1 and 2.

By dividing the core of the shunt-solenoid as I have described I amenabled to employ a comparatively-weak solenoid in the lamp circuit forthe following reasons. In the act of striking the are, which usuallydemands considerable effort, the main solenoid, being aided by the otherconspiring with it, has to exert less effort, and afterward when thedivided core becomes virtually undivided by the attraction of its partsthe two cores act conjointly t0 efiect the slight upward move ments ofthe upper carbon when it slips a little too far down in the act offeeding. The use of a comparatively-weak solenoid in the lamp-circuit isof great advantage in rendering the lamp less sensitive to variations ofcurrent. Thesensitivenessisfurtherreduced by the winding of theshunt-coil with a few convolutions which are in the lamp-circuit,because when the strength of the main current increases, increasing theforce of the main solenoid, it adds, also, to the force resulting fromthose convolutions of the shuntsolenoid, this force acting in oppositionto that of the main solenoid.

Having thus described the nature of myinvention and the best means Iknow of carrying it out in practice, I claim- 1. In the regulatingmechanism of an elec trio-arc lamp, the combination of two solenoids,the one having a coil of coarse wire in the lamp-circuit and an integralcore linked to one arm of a lever, the other having a coil of fine wirein a shunt to the lamp-circuit and a divided core, part of which islinked to the opposite arm of the said lever, which lever is linked tothe carbon-feeding device, substantially as and for the purpose setforth.

2. In the regulating mechanism of an electric-arc lamp, the combinationof two solenoids, the one having its coil of coarse wire in qhelamp-circuit and an integral core linked to one arm of a lever, theother having acoil of fine wire in a shunt to the lamp-circuit, alongwith a few convolutions of coarse wire in the lamp-circuit, and havingadividedcore part of which is linked to the opposite arm of the saidlever, which lever is linked to the carbon-feeding device, substantiallyas and for the purpose set forth. 3. In the regulating mechanism for anelectric-arc lamp, the combination of two solenoids, the one having itscoil in the lamp-circuit and a divided core part of which is linked tothe carbon-feeding device and part to one arm of a lever, the otherhaving its coil in a shunt to the 1amp-circuit and an integral corelinked to the opposite arm of the said lever, substantially asdescribed.

In testimony whereof I have signed my name to this specification, in thepresence of two subscribing witnesses, this 21st day of July, A. D.1891.

JAMES BROCKIE.

lVitnesses:

OLIVER IMRAY, Patent Agent, 28 Southampton Buildings,

London, W. C.

JNO. P. M. MILLARD, Clerk to Messrs. Abel &: Immy, Consulting Engineersand Patent Agents, 28 Southampton Buildings, London, W. C

